Make the Right In-Season Water Call for Row Crops Under a Dry Spell
Water management during drought conditions can make or break a row crop season. This article brings together research-based recommendations and field-tested strategies from agronomists and irrigation specialists to help growers determine when supplemental water is truly needed. Learn how to assess soil moisture at the root zone and make data-driven irrigation decisions that protect yield without wasting resources.
Probe the Root Zone First
When a dry spell hits, I do not make the call from the forecast alone. In landscaping, the better question is what the soil and the plant are telling you right now. If the root zone is dry, new growth is softening, or a recently planted area has not established properly yet, waiting on rain can be a costly gamble.
The guideline I trust most is to check moisture below the surface before deciding. The top can look dry while the root zone is still holding enough moisture, or the top can look fine while the plant is already struggling deeper down. A quick soil check gives you a better read than guessing from the weather app.
If the soil still has useful moisture, I would lean on mulch, shade where practical, weed control and watering at the right time of day. If the root zone is drying out during a key establishment stage, I would irrigate deeply rather than doing light, frequent watering.
The aim is not to water more. It is to water when it will actually protect the plant and help the roots chase moisture, rather than creating shallow, weak growth.
Calculate Needs With ET Plus Kc
Irrigation should match how much water the crop uses each day based on evapotranspiration and the crop coefficient for its growth stage. Local weather or a nearby station can provide reference ET, which is then multiplied by Kc to estimate crop water use. Subtract recent effective rain and convert the net need to run time using the system’s application rate. Soil type and rooting depth help set how much water can be used before stress begins.
Update Kc as the canopy changes and use short weather forecasts to plan ahead. Lock in a weekly schedule and adjust it after checking field moisture. Calculate today’s ET times Kc and set the next irrigation run now.
Irrigate at Night to Cut Losses
Watering at night limits losses because the air is cooler and the wind is usually lighter. Lower evaporative demand means more of each inch applied reaches the root zone. Gentler conditions also reduce drift and improve sprinkler uniformity. Where power rates vary, night runs can trim energy cost without extra hardware.
Safety matters after dark, so use good lighting, clear paths, and alerts for pressure drops. Timers and soil moisture setpoints can start and stop runs to prevent overwatering. Plan the next irrigation window for night hours and set the controls today.
Verify Distribution Uniformity Then Fix Issues
Uniform application across the whole system protects yield and saves water. Match nozzle size and spacing to the target application rate and the machine’s travel speed. Use pressure regulators so each nozzle delivers the right flow across slopes and wind. Choose droplet size that reduces drift yet avoids soil sealing on fine soils.
Run a quick bucket test to find low or high spots, leaks, and plugged tips. Fix issues, set the right speed, and confirm overlap so the field gets the planned depth. Schedule a uniformity check this week and adjust nozzles and pressure setpoints now.
Adopt Targeted Deficit to Save Water
Regulated deficit irrigation saves water by giving slightly less than full crop use during growth stages that can handle mild stress. Do not reduce water during flowering, pollination, or early grain fill, when yield is most at risk. Aim for gentle stress during mid-vegetative growth or late ripening, and watch for leaf roll or slowed growth. Set an allowable soil water loss and keep stress within that band using shorter, well-timed sets.
Some crops may even improve in quality, but heat and salinity can raise risk, so watch soil and weather closely. Use sensors or careful field checks to stay inside safe limits and recover quickly after hot spells. Pick the stages for reduced water today and write a clear plan with start and stop points.
Prioritize Sensitive Blocks During Dry Spells
Under a dry spell, water should go first to fields where stress will hurt yield the most. Crops at flowering or early fruit set are often most sensitive, while vegetative stages can handle brief stress. Sandy or shallow soils dry faster and may need smaller, more frequent sets. High-value blocks or key contract acres may return more per inch of water.
Use field notes, soil maps, and plant stress signs to rank fields each week. Shift water to the top group until they stabilize, then rotate to the rest. Make a simple ranking today and schedule the next runs in that order.